Thermostat.



No. 7|4,8l0. Patented. Dec. 2, I902.

A. T. LE VESGQNTE. THERMUSTAT.

[Application filed. Feb. 7, 1901.)

(No Mo del.)

Zfliii 666136. I I7? z/wzion www w ITHO WASHINGTON o c UNITED STATESPATENT OFFICE.

ALFRED T. LE VESOONTE, OF MINNEAPOLIS, MINNESOTA.

THERMOSTAT.

SPECIFICATION forming part of Letters Patent No. 714,810, dated December2, 1902. Application filed February 7, 1901. Serial No. 16,311. (Nomodel.)

To (ZZZ whom, it ntay concern.-

Be it known that LALEEED T.Ln VESOONTE, a citizen of the United States,residing at Minneapolis, in the county of I-Iennepin and State ofMinnesota, have invented certain new and useful Improvements inThermostats; and I do hereby declare the following to be a full, clear,and exact description of'the invention, such as will enable othersskilled in the art to which it appertains to make and use the same.

My invention has for its object to provide an improvement inthermostats; and to this end it consists of the novel devices andcombinations of devices hereinafterdescribed,and defined in the claim.

More specifically stated, my invention relates to thermostats forcontrolling electric circuits for sounding alarms or for doing similarwork; and it consists of a bulb or liquidcontaining compartment having adiaphragm the movement of which makes and breaks contact between theelectrodes of the electric circuit. In this bulb or compartment a liquidis placed, and the diaphragm is arranged to be actuated by the boilingof the liquid. For most purposes the electric circuit should be closedand the alarm sounded at quite low temperatures compared with theboiling-temperature of water. I-Ience liquids other than water mustusually be employed. Chlorid of ethyl,which boils at 54 Fahrenheit,aldehyde, which boils at 69 Fahrenheit, sulfuric ether, which boils at95 Fahrenheit, sulfid of carbon, which boils at 114 Fahrenheit, andbromin, which boils at 145 Fahrenheit, may be used within the bulb,according to the temperature at which it is desired to operate thethermostat. For other temperatures other liquids or combinations ofliquids may, of course, be used.

The invention is illustrated in the accompanying drawings, whereinlikecharacters indicate like parts throughout the several views.

Figure 1 is a view in side elevation, showing one of my improvedthermostats. Fig. 2

is a section on the line :0 00 of Fig. 1, showing the thermostat securedto the end of a tube. Fig. 3 is a side elevation showing another of myimproved thermostats, which varies somewhat in construction from thatshown in Figs. 1 and 2; and Fig. 4 is a section taken centrally throughthe thermostat shown in Fig. 3.

In the construction illustrated in Fig. 1 two outwardly-bulgedconcavo-conveX sections 1 2 are soldered together and to the margin of adiaphragm 3, as indicated at 4: in Fig. 2.

the same preferably having a patinnm point 9, which is normally out ofcontact with a platinum contact-piece 10 on said diaphragm. One of thelead-wires 11 connects to the screw or electrode 8, while the otherconnects to the bulb-section 1.. The said section 1 is a metal and hascontact with the metal diaphragm 3. In Fig. 2 the hub of the section 2is shown as connected to a supporting pipe or tube 12 by means of acoupling-sleeve 13.

The construction illustrated in Figs. 3 and 4. is very much the same asthat above described. The bulb or liquid-containing compartment in thiscase is formed by a hollow head 14, having soldered to its upper andotherwise open face a diaphragm 15. The head 14 is provided with apassage 16, normally closed by plug 17, but affording when open apassage through which the liquid may be introduced into the bulb. A yoke18, extending diametrically across the upper face of the head 14,affords a support for an insulating-bushinglt). Ascrew20,whichserves asan electrode, extends through the bushing 19, the same as in theabove-described construction. Also, as shown, the electrode 20 isprovided with a platinum contact-point 21, and thediaphragm 15 has aplatinum contact-piece 22. I

The operation of both devices is substantially the same, and in thefollowing description of the operation attention is directed to Figs. 1and 2. It is evident by inspection of Fig. 2 that the circuit throughthe wires 11 is normally broken between the needle-point 9 of theelectrode 8 and the contact-piece 10 of the diaphragm 3. The bulb ispreferably only partially filled with the liquid 2, which liquid we willassume to be sulfuric ether. It is of course evident that when 95Fahrenheit is exceeded in the temperature of the atmosphere or medium incontact with the liquid-containing bulb the said liquid will be boiledand upon being converted into vapor will expand and by its pressureforce the contact-piece 10 on the diaphragm into contact with theplatinum point 9 of the electrode 8, thereby closing the circuit andsounding the alarm or performing whatever work is to be performed by theclosing of the circuit.

Of course the construction might be reversed and the arrangement be suchthat the circuit will be held normally closed and be broken or opened bythe movement of the diaphragm or other movable part under the expandingpressure of the created vapor.

As one of the lead or circuit wires 11 is passed through the supportingtube or pipe 12, itis kept out of contact with'the surrounding grain ormaterial, so that the said connection 11 cannot be short circuited eventhough the surrounding grain be damp or wet.

What I claim, and desire to secure by Letters Patent of the UnitedStates, is as follows:

The combination with a thermostat, comprising a liquid-containingchamber having a diaphragm which is moved by pressure generated Withinsaid chamber, a pipe or tube supporting said diaphragm a pair ofelectrodes movable in and out of contact by said diaphragm, and leads tosaid electrodes, one of which is passed axiallythrough the saidsupporting pipe or tube, whereby short-circuiting by a surroundingmaterial is prevented, substantially as described.

In testimony whereof I affix my signature in presence of two Witnesses.

ALFRED T. LE VESCONTE.

WVitnesses:

ANNE S. READ, F. D. MERCHANT.

